Prevalence and Predictors of Utilization of Community Pharmacy Generic Drug Discount Programs

BACKGROUND: Since 2006, select pharmacies in the United States have been offering programs where prescriptions for certain generic medications can be filled at very low cost (e.g., a 30-day supply for $4). However, limited knowledge exists on the characteristics of patients who have used these services. OBJECTIVES: To examine the prevalence of use of community pharmacy generic drug discount programs and the characteristics of patients using these programs. METHODS: Two cross-sectional surveys of patients in a university-affiliated health system general medicine clinic were conducted over an approximately 4-week period in the summers of 2008 and 2010. The survey measured self-reported information in 3 parts: a listing of current medications, questions about program use, and patient demographics. The survey was administered to patients as they were waiting to see their physicians with a research assistant on-site for assistance and to collect the completed surveys. Medications listed by patients were classified as acute or chronic by pharmacists on the research team. Descriptive statistics (Pearson chi-square or Student’s t-tests) were used to compare subjects across years and between groups of discount program users and nonusers. Logistic regression models were constructed to identify significant predictors of program use, testing demographic factors, prescription drug coverage, number of medications, monthly out-of-pocket payments, and year of the survey. RESULTS: The convenience sample included 414 individuals overall, 203 in 2008 and 211 in 2010. After excluding respondents who did not answer all survey questions, the sample size was 311 (n=148 in 2008 and 163 in 2010). The sample was mostly Caucasian; most patients had prescription coverage; and a large majority of medications filled were for chronic use. Patient characteristics were similar in the 2 groups except for a higher mean number of self-reported medications in 2010 than 2008 (4.2 vs. 3.4, respectively, P=0.01). Use of a discount medication program was reported by 52 (31.9%) of those surveyed in 2010 compared with 7 (4.7%) in 2008 (P less than 0.001). When both groups were combined, factors associated with use of generic drug discount programs included filling prescriptions for a higher number of medications (odds ratio [OR]=1.13, 95% CI=1.01-1.27, P=0.036) and the year of the survey (OR for 2010=9.02, 95% CI=3.8221.29). Differences in program use were also observed among categories of age and income. CONCLUSIONS: Over a 2-year period, there was an increase in the use of discount generic medication programs in this university clinic population. Patients who take more prescription medications are more likely to choose such plans, and differences in program use were observed between ranges of age and income. More extensive analysis is needed to better predict patient use of such services.

• An increase in the uptake of discount generic medication programs from 4.7% in 2008 to 31.9% in 2010 was observed using a convenience sample of patients in an adult internal medicine clinic in a midwestern city. • The likelihood of program use was significantly higher in patients using a greater number of medications.

B R I E F C O M M U N I C AT I O N
B etween 1999 and 2009, the total number of prescriptions dispensed in the United States increased by 39%, while the average number of retail prescriptions per capita increased from 10.1 to 12.6. 1 According to the Centers for Disease Control and Prevention, nearly 50% of American adults are now taking at least 1 prescription medication. 2 The increase in prescribing per patient along with the increase in cost of medication has led to an increase in out-of-pocket spending for prescription drugs. 3 As a result, many patients elect to not fill prescriptions or cut back on usage. 4,5 Recently, the U.S. prescription drug market has been bolstered by increased generic entry. 6 Such growth has been coupled with insurer-driven efforts to improve generic drug utilization. In the hopes of attracting new customers and growing pharmacy business, chain community pharmacies began offering discount generic programs in the fall of 2006, typically offering a 30-day supply of certain generic medications for $4 or a 90-day supply for $10-$12. 7 Such programs experienced rapid expansion: availability and utilization had reached 25,000 pharmacies nationwide and nearly 70 million Americans, respectively, by 2008. 8 While several years of data currently exist on the uptake of these programs, relatively little has been published about the patients who use such services. means with standard deviations or frequencies with percentages. All reported drugs were categorized as either "chronic" or "acute" based on their generally intended use as assessed by the clinician team members. Pearson chi-square tests or Student's t-tests were used to compare differences between 2008 and 2010 and between groups of patients who had and had not used discounted programs. A P value of < 0.05 was used to determine statistical significance.
Logistic regression was used to identify significant predictors of discounted generic program use. The variables for patient characteristics that were included in the model were year of survey, age group, gender, race/ethnicity (Caucasian vs. all others), insurance coverage, number of medications, annual household income group, and average monthly outof-pocket prescription payment group. Categorical variable groups included age in years (younger than 30, 30-49, 50-64, 65 or older), average household income by quartiles (≤ $24,000, $24,001-$50,000, $50,001-$85,000, > $85,000), and average monthly out-of-pocket prescription payments in thirds (≤ $10, $11-$40, > $40). Age categories were created according to distinct groups in the general population, such as young adults, those of pre-retirement age, and those who were eligible for Medicare. Categories for income and monthly out-of-pocket payment represent evenly distributed groups within the data after adjusting these values to 2010 dollars using the Consumer Price Index. 9 Unadjusted bivariate logistic regression analyses were conducted first in order to determine individually significant predictors of program use. Subsequently, variables were entered into the multivariate model using forward conditional, stepwise model construction (P value < 0.10) in order to obtain a final, adjusted analysis. A Wald test was used to generate a P value for differences among groups of each categorical variable in both the unadjusted and adjusted analyses. PASW Statistics 18 (IBM SPSS) and STATA 11 (Stata Corp, College Station, TX) were used for all statistical analyses.

Sample Characteristics
The respondent sample included 414 individuals, 203 in 2008 and 211 in 2010. Of these, 311 completed surveys were further analyzed. Comparison between the included and excluded responders found that persons who did not complete the survey were more likely to be older (mean age = 57.8, P < 0.001) or male (n = 56 [57%], P = 0.037). Respondent characteristics from 2008 and 2010 were similar with the exception that the mean number of medications reported by subjects increased from 3.4 in 2008 to 4.2 in 2010 (P = 0.01; Table 1).

Discount Program Use
A significant increase in the number of individuals using a discounted medication program was observed over time in The objective of this study was to document the uptake of program use and to identify the characteristics of those who have been using discounted generic medication programs to date.

■■ Methods Study Procedures
The study consisted of 2 identical cross-sectional surveys conducted during 4-week periods in the summers of 2008 and 2010 in an adult general internal medicine clinic of a university-affiliated health system located in a midwestern city. The surveys were intended to assess uptake of the discount generic medication programs in separate years, allowing for the assessment of changes in program use over time. A convenience sample was used to select subjects who were aged 18 years or older and actively taking at least 1 prescription medication at the time. Patients were approached by a research assistant in the clinic reception area, where they were asked to participate. Prior to agreeing to participate, subjects were given a detailed explanation of the project, and their completed survey indicated their consent. The survey was given in paper format with the research assistant present to assist respondents. No identifiable information was taken from study participants. Completed surveys were returned to the research assistant prior to leaving the clinic. The University of Michigan Institutional Review Board approved the study.
The survey (Appendix) contained self-reported information on the patient's most recent prescription medication use in 3 parts. Patients were first asked to list each current prescription medication, the pharmacy where it was last filled, the price paid, whether or not the medication was a brand or generic, and if it was filled using a discounted generic program. For purposes of the survey, a discounted generic program was described to the patients in the survey document as a service whereby a 30-day supply of medication was sold for $4.00 or a 90-day supply for $10.00. The survey was pre-tested in a comparable patient population to clarify instructions and questions, following which no changes were deemed necessary.
Subjects were then asked about their discount program use and, finally, requested to detail several personal characteristics, including prescription drug insurance coverage (yes vs. no), average amount paid per month for medications (U.S. dollars), gender, age (years), race (Caucasian, African American, Asian, Hispanic, Native American, Other), and average annual household income (U.S. dollars). No incentives were offered to those participating, and responses given at the time of the survey were assumed to be accurately reported by each respondent.

Statistical Analysis
Only fully completed surveys were considered for analysis in order to limit the bias in the results. Data for patient characteristics were compiled in total and by year and presented as this sample, climbing from 4.7% (n = 7) of those surveyed in 2008 to 31.9% (n = 52) of those in 2010 (P < 0.001; Table 1). Overall, 19.0% (n = 59) of respondents indicated they had used a discount medication program. A total of 817 (58.4% of all medications reported) generic medications were reported by the respondents; 28.2% of all medications reported were reportedly filled using a discount medication program. Most of the medications reported (84.1%) were filled for chronic use; of those filled using a discount program, 90% were for chronic use.

Discount Program Group Comparisons
Program users had a mean age of 49 years, were well balanced by gender, and 86% had prescription drug coverage, consistent with statewide estimates of insurance coverage. 10 Compared with those who had not used a discount program, program users reported a greater number of prescription medications on average ( Table 2).

Predictors of Program Use
Unadjusted logistic regression analyses revealed that patient age, annual income, and the number of medications were significant individual predictors of program use (Table 3). Gender, race, and average monthly medication spending were not sig-nificantly related to using a discount generic medication program. Additionally, prescription insurance coverage trended toward statistical significance, indicating that those without coverage may be more likely to use discounted medication programs (P = 0.089); however, there were only 25 respondents without prescription insurance, only 8 of whom were program users, in the sample.
Stepwise analyses constructed the final model where ultimately 2 characteristics were significant predictors of program use: year (P < 0.001) and the number of medications (P = 0.036) after adjustments for age group, year, and income (Table 3). Each additional medication filled was associated with a 13% increase in the odds of using a program.
Post-estimation analyses also showed that the odds of using a discount medication program differed by age group (P = 0.016) but, compared with subjects aged 30 years or younger, no individual group was significantly more likely to have used a discount program (Table 3). A similar finding for the effect of annual income group was observed: the odds of using a discount program differed by income group (P = 0.031) but no individual income range was significantly more likely to have used a program compared with those reporting annual incomes greater than $85,000.

■■ Discussion
The results of this study demonstrated an association between discount generic medication program use and 3 patient characteristics. These predictors included ranges of annual incomes, the filling of a higher number of medications, and age ranges. Program use rates increased from 4.7% of survey respondents in 2008 to 31.9% in 2010.  Although still relatively new, discount generic medication programs have become a popular mechanism by which access to and affordability of effective treatments may be bolstered. Observational studies examining adherence and persistence have, on multiple occasions, shown an association between the cost of medications and poor patient treatment adherence; [11][12][13][14][15] however, the relationship between decreasing the cost of medication and the resulting adherence is still under debate. 16 Future research should examine whether the availability of medications through discounted programs improves medication-taking behavior.

Prevalence and Predictors of Utilization of Community Pharmacy Generic Drug Discount Programs
Since inception, discount generic medication programs have caught the attention of health care providers, managed care organizations, the public, and even government entities. 17 Although providing benefits to many, these programs have raised some criticism, such as claims of "predatory pricing," whereby the product volume of some community pharmacies allows for the dropping of medication prices below cost. 17 Smaller competitors, unable to do so and still make a profit, are potentially left at a competitive disadvantage. 17,18 Additionally, concerns over the effect on quality assurance practices have arisen, 7,18 including incomplete claims histories that result from the absence of the need to file a claim for insurance reimbursement. 7 As a result, incomplete linkage between the patient's entire health record affects a third party's or pharmacy's ability to track and respond to potential medication-related problems. Although community pharmacy generic drug discount programs may contribute to incomplete pharmacy claim databases, these programs increase the affordability of drugs and potentially reduce health care spending for payers and patients.
Intuitively, the discount generic medication programs were expected to be most attractive to persons without prescription drug insurance. We found 87% of the persons using these programs had prescription drug insurance, meaning that the availability of such programs to minimize medication costs may be attractive to patients regardless of prescription insurance status.

Limitations
First, the survey was administered to a convenience sample of patients from a single university general medicine clinic. As such, the results may not be generalizable to or representative of a larger population. Second, the convenience sampling method and the small number of participants reporting discount program use in 2008 limited the statistical analysis, especially the ability to examine specific predictors of program use. Subsequently, assessment of differences in predictors of program use between sampling years was not possible; adequate statistical analysis of predictors could be made only using both sampling years combined. As a result, the findings may be biased, since factors affecting program use may differ between the 2 years, including changes in the availability and knowledge of such services. Specifically, the number of prescription drug products available in the discounted medication program and the number of pharmacies offering these programs were not included in the study. It may be that one or both of these factors would have influenced use of the discounted medication programs. Third, the study did not match the generic drugs available in the various discounted medication programs with the generic drugs reported by the patient. This process would have refined the analysis. However, given the large number of generic products available at the discounted medication programs (ranging from 500 to 3,000 generic products touted on various national chain websites), the expected impact of this limitation is minimal. Fourth, the study required respondents to recall specific information about their prescription medications; although a pre-test of the survey was performed, no tests of reliability or validity were performed. However, as part of routine patient care, the study clinic asks patients to bring their prescription vials to their appointments. Thus, this potential recall bias was minimized by asking the respondents to complete the survey while waiting for their clinic appointments. Additionally, the analysis did not account for potential differences in the mix of drugs taken by the respondents, which could have further biased the results, especially the effect of age.

■■ Conclusions
Over 2 surveys of patients from a university general medicine clinic, an increase in discount generic medication program use was observed between 2008 and 2010. Subjects taking more medications were more likely to have used a generic drug discount program. Differences in program use were also observed between ranges of age and income, but the results warrant further investigation.

DISCLOSURES
The authors report no financial or other conflicts of interest related to the subject or products discussed in this article.
Concept and design were performed by Erickson, Kucukarslan, Truong, and Tungol. Truong and Tungol collected the data. Gatwood interpreted the data with the assistance of Truong and Tungol. Writing of the manuscript was shared equally by all authors. The manuscript was revised by Gatwood with the assistance of Erickson and Kucukarslan.